Pressure control for duplicating machines



Nov. 8, 1955 H. P. KElL PRESSURE CONTROL FOR DUPLICATING MACHINES FiledJune 30, 1952 4 Sheets-Sheet 1 IN V EN TOR.

A erzcg PK e21 BY H. P. KEIL 2,722,885

PRESSURE CONTROL FOR DUPLICATING MACHINES 4 Sheets-Sheet 2 Nov. 8, 1955Filed June 50, 1952 By %M% M;

NOV. 8, 1955 H, P, KE

PRESSURE CONTROL FOR DUPLICATING MACHINES 4 Sheets-Sheet Filed June 30,1952 INVENTOR. Hirzry D {ell %w//MZl Nov. 8, 1955 H. P. Kl ElL 72,722,885

PRESSURE CONTROL FOR DUPLICATING MACHINES Filed June 50, 1952 4Sheets-Sheet 4 INVENTOR Henry P Kil United States Patent PRESSURECONTROL FOR DUPLICATING MACHINES Henry P. Keil, Chicago, Ill., assignorto The Fixture Hardware Corporation, Chicago, 111., a corporation ofIllinois Application June 30, 1952, Serial No. 296,283

Claims. (Cl. 101-132) The present invention relates to improvements inthe pressure control for duplicating machines of the type shown inapplication, Serial No. 279,287, which I filed March 29, 1952, forimprovements in Duplicating Machines. In a machine of this character thedrum carries a master copy which has the legend to be reproduced placedthereon in hectographic ink and in reverse to what it is to appear onthe copies. Copy sheets are fed into engagement with the master sheet onthe drum and moistened on the surface that engages the master copy onthe drum with a solvent for the hectograph ink. The copy sheets arepressed into intimate engagement with the master copy by a small roller.It is necessary to maintain the proper pressure between the small rollerand the drum in order to obtain the best copies. This is particularlytrue in the machine shown in my prior application wherein the drive ofthe moistening mechanism is accomplished through engagement of the drumwith the pressuer roller and a drive by the pressure roller of thefeeding and moistening rollers that advance and moisten the copy sheet.In this machine, provision is made for releasing the pressure betweenthe pressure roller and the drum and between the moistening rollercouple at the end of each run of copies.

It is the purpose of the present invention to provide a novel mechanismby which the pressure of the pressure roller toward the drum iscontrolled in such a way that the repeated release and engagement of thepressure roller with the drum can be accomplished without interferingwith the pressure adjustment and the pressure adjustment may be changedat any time.

It is also a purpose of the present invention to provide a novelconstruction embodying the pressure roller and its supporting arms, apressure release mechanism by which the pressure roller is separatedfrom the drum, together with a novel pressure adjusting mechanisminterposed in the release mechanism for regulating the amount ofpressure between the drum, and the pressure roller when they areengaged.

The nature and advantage of my invention will appear more fully from thefollowing description and the accompanying drawings wherein a preferredform of the invention is shown. it should be understood however, thatthe drawings and description are illustrative only and are not intendedto limit the invention except insofar as it is limited by the claims.

In the'drawings:

Figure 1 is a sectional view taken longitudinally through theduplicating machine of my prior application mentioned hereinbefore,showing the mechanism by which the pressure roller and the associatedmoistening roller assembly are interconnected with the drum;

Figure 2 is a plan sectional view taken substantially on the line 2-2 ofFigure 1;

Figure 3 is a sectional view taken substantially on the line 3--3 ofFigure 2, but showing the parts in operating po'sitionwith the pressureroller in engagement with the drum;

2,722,885 Fatented Nov. 8, 1955 Figure 4 is a fragmentary sectional viewtaken on the line 4--4 of Figure 3;

Figure 5 is a sectional view taken on the line 55 of Figure 2; and

Figure 6 is a fragmentary sectional view taken on the line 66 of Figure2, looking at the same mechanism as Figure 3 but in the oppositedirection.

Referring now in detail to the drawings, a duplicating machine embodyingmy invention employs a drum 10 to support a master sheet. A suitablegripping mechanism 11 is provided on the drum for holding a master sheetand copy sheets are fed to the drum from a feed tray 12 by moisteningand feeding rollers 13 and 14. The moistened copy sheets are pressedagainst the drum by a pressuer roller 15. The drum 10 is rotated bymeans of its shaft 16a and an operating handle, not shown. The presentinvention concerns itself with the mechanism whereby the pressure of theroller 15 against the drum is readily adjusted in a machine of thischaracter and retained at the desired adjustment even though thepressure roller 15 may be shifted many times between its operativeposition as shown in Figure 3, and the released position shown inFigure 1. The pressure roller 15 is connected by a mechanism, describedhereinafter, to the roller 14, once during each duplicating cycle of thedrum, in order to advance copy sheets to the drum.

As shown best by Figures 1 and 2, the rollers 14 and 15 are supported bylevers 16 and 17 which are pivoted to the side frames 18 and 19, pivotpins 20and 21 being provided on the side frames 18 and 19 for thispurpose. The roller 15 has bearing members 22 and 23 at its ends thatseat in recesses in the tops of the levers 16 and 17. The roller 14 alsohas bearings 24 and 25 at its ends, which bearings are supported innotches in the levers 16 and 17. The roller 13 has its shaft 13a mountedin brackets 26 and 27, which brackets are pivotally supported in theends of a moistening liquid trough 28. Yielding pressure is applieddownwardly on the roller 13 through a transfer roller 29, a portion ofwhich is shown in Figure 3, and the shaft 29a of which is shown inFigure l of the drawings. The members 30 exert a downward pressure onthe shaft 29a when the rollers 14 and 15 are raised. The pressure isexerted through the medium of springs 31, levers 32 and links 33 whichconnect to the levers 16 and 17 The details of this mechanism are shownmore fully and described in my prior application referred tohereinbefore. They are described here merely to give sufficientbackground for the understanding of the present invention.

Referring now in particular to Figures 2 and 5, the drum 10 has acontrol cam 34 at the end thereof adjacent to the side frame 19. Thiscontrol cam is adapted to engage a roller 35 which is mounted in thefree end of a lever arm 36 that is pivoted to the pivot pin 21 for thelever 17. The rollers 14 and 15 have knurled wheels 37 and 38 on theirshafts 14a and 15a beyond the bearings 25 and 23. These wheels 37 and-38 are adapted to be engaged by a connecting wheel 39 that is carried onthe lever arm 36 whenever the flat portion 34a of the cam 34 is oppositethe roller 35 on the lever arm 36. The wheel 39 preferably has its drivesurface made of some yieldable material such as synthetic rubber so thatit will have adequate driving engagement with the wheels 37 and 38 totransfer the rotative movement of the pressure roller 15 to themoistening and feeding rollers13 and 14. The lever arm 36 is yieldinglypressed in a direction to engage the wheel 39 with the wheels 37 and 38by a have adjustable step pins 43.

in my prior application, are adapted to engage rollers 45 and 46 thatare provided on trip levers 47 and 48. The trip levers 47 and 48 arefixed to a floating shaft 49 that extends between the side frames 18 and19 and fits in bosses 50 and 51 on the side frames 18 and 19respectively. These bosses have enlarged openings, as shown at 52 inFigure 4, to receive the ends of the floating shaft 49. The trip lever47 is connected by a .plate 53 fixed thereto, and .a link .54 to a handlever 55 which controls the master sheet .gripping mechanism 11 on thedrum and provides a lock for the drum through the levers 56 and 57 andthe spring 58. The details of this control are old as shown .in myapplication, Serial No. 791,881, filed December 15, 1947, for a motordriven duplicating machine. The lever 55 has a handle 59 that projectsbeyond the side frame 18 so that it is readily accessible. A togglespring .mechanism 60 is provided between the member 53 and a bracket 61on the side frame 18 to hold the trip levers 47 and 48 in either theposition shown in Figure 2 or that shown in Figure 3.

It will be appreciated that by adjusting the floating shaft 49horizontally toward and away from the stop members 43 and 44, the levers16 and '17 can be made to exert more or less pressure to hold thepressure roller against the drum 10. This adjustment must be such thatthe control mechanism just described, continues to perform its functionin all positions. The shaft 49 has two links 62 and 63 fitted over it atthe ends adjacent to the bosses 50 and 51. These links extendhorizontally inside the side frames 18 and 19 and are supported at theirforward ends by a cross shaft 64 and eccentrics 65 and 66 which arefixed to the cross shaft 64 and journalled in the links 62 and 63respectively. The links 62 and 63 are guided by guide pins 67 and 68which are secured in bosses 69 and 70 on the side frames 18 and 19. Theshaft 64 has a hand piece 71 thereon outside the side frame 18. Byrotating the .hand piece .71, the earns 65 and 66 may be made to movethe links 62 and 63 endwise a limited amount which will of course, movethe shaft 49 toward or away from the stop members '43 and 44. Thislimited movement is not great enough to interfere with the controloperations of the members 54, .55, '56, 57 and 58, yet it provides amplevariation in the pressure of the roller 15 against the drum 10 when theparts are in the position illustrated in Figure 3.

It is believed that the nature and advantage of my invention will beapparent from the .foregoing description.

Having thus described my invention, 1 claim:

1. In a duplicating machine, side frames, a master sheet supporting drummounted for rotation in said frames, a pressure roller beneath the drumfor pressing sheets against the drum, levers supporting the ends of thepressure roller and pivotally supported by the frames to carry theroller into and out of pressure contact with the drum, said levershaving depending portions for engagement with trip levers to move thepressure roller carrying levers in a direction to lift the pressureroller, a pressure control shaft journalled in the frame, a handle onthe control shaft, eccentric cams fixed on the pressure control shaftadjacent to the side frames, links journalled on the cams, a rock shaftjournalled in the free ends of the links, means on the frame supportingthe free ends of the links and said rock shaft for movement endwise ofthe links in response to rotation of said eccentric cams, trip leversfixed on the rock shaft in alignment with the depending portions of said:pressure roller levers, and means to turn the rock shaft.

2. In a duplicating'machine, side frames, a master sheet supporting drummounted for rotation in said frames, a pressure roller beneath the drumfor pressing sheets against the drum, levers supporting the ends of thepressure 'rollerand pivotally'supported by-the fr'ames to carry theroller into and out of pressure contact with the drum, said levershaving depending portions for engagement with trip levers 10.-move thepressured-tiller carrying, levers in a direction to lift the pressureroller, a pressure control shaft journalled in the frame, a handle onthe control shaft, eccentric cams fixed on the pressure control shaftadjacent to the side frames, links journalled on the earns, a rock shaftjournalled in the free ends of the links, means on the frame supportingthe free ends of the links and said rock shaft for movement endwise ofthe links in response to rotation 'of said eccentric cams, trip leversfixed on the rock shaft in alignment with the depending portions of saidpressure roller levers, a toggle spring mechanism connected to one ofsaid trip levers and the adjacent side frame, operable to hold the triplevers either in a position to separate the pressure roller and drum, orin position to lift the pressure roller against the drum, a hand lever,and a link connecting the hand lever and one of said trip levers formoving the trip lever between the aforesaid positions.

3. In a duplicating machine having a master sheet drum, and a pressureroller movable between operative position in .pressure engagement withthe lower surface of the drum and inoperative position spaced below thedrum, and having rock levers carrying the pressure roller together witha shaft having means to shift said levers from inoperative to operativeposition, a support for said shaft comprising links in which the ends ofsaid shaft are journalled, means supporting the links for endwisemovement, a pressure control shaft spaced from the first named shaft,eccentrics on said last namedshaft on which said links are journalled,and a handle .for turning the pressure control shaft.

4. In a duplicating machine, side frames, a master sheet supporting drummounted for rotation in said frames, a pressure roller beneath the drumfor pressing sheets against the drum, levers supporting the ends of thepressure roller and pivotally supported by the frames to carry theroller into and out of pressure contact with the drum, said levershaving depending portions for engagement with trip leversto move thepressure roller carrying levers in a direction to lift the pressureroller, a pressure control shaft journalled in the frame, eccentric camsfixed on the pressure control shaft adjacent the side frames, linksjournalled on the cams, a rock shaft journalled on the free ends of thelinks, loosses on the side frames adjacent the rock shaft, shaftreceiving slots in the bosses, the end of the rock shaft being seated insaid slots, said slots being elongated horizontally to secure the rockshaft for limited horizontal movement in response to rotation of theeccentric cams, trip levers mounted on said ro'ck shaft in alignmentwith the depending portions of the pressure roller supporting levers,and means on the rock shaft to rotate the rock shaft.

5. In a 'duplic'atin'g machine "having a master sheet drum and apressure roller for pressing sheets against said drum, means supportingthe pressure roller against said drum whereby the movement of "theroller against the drum is individually controlled at both ends of theroller, and means for varying 'the pressure of the roller against thedrum while maintaining the individual movemerit of the ends of theroller toward the drum, said first named means comprising separatelevers pivoted to the side frames of the machine, each lever supportingone end of the pressure roller, said levers having depending portionsthereon, adjustable stops mounted at thelower edges of the dependingportions of said levers, a rock shaft mounted in the side frames, triplevers mounted on the rock shaft in alignment with the adjustable stops,.said stopspressing against the trip levers to hold the ends of thepressure roller in contact with the drum, said pressure varyingmeanscomprising bosses in theside frames, slots in the bosses receiving theendsof the rock shaft, said slots being elongated .in a directionparallel to the direction :of adjustment of the stops to allow :the rockshaft References Cited in the file of this patent UNITED STATES PATENTSWildersoon July 10, 1945 Rundblad Nov. 6, 1951 Ford et a1 .a June 23,1953

